Research On Rollover Warning And Active Anti-rollover Control Strategy Of School Bus

Compared with other vehicles, school bus has higher center of gravity and biggersurface area, it will have a very large centripetal force, which leads to the lateralstability low and prone to rollover accident. Therefore, researching the rolloverwarning and active anti-rollover control of school bus has a very important practicalsignificance to enhance the vehicle security.Firstly, a three degrees of freedom dynamic model that can accurately reflect therollover characteristics is established. This model consists all the importantcharacteristics about lateral, yaw and roll, which can content the demand of stabilitycontrol. At the same time, the paper analyzes the influence that the parametersimpacted on the lateral stability, reveals the intrinsic relationship between roll stabilityand these parameters.Secondly, an optimized TTR rollover warning algorithm based on T-S fuzzyneural network is presented according to the motion characteristics of school bus. Therollover stability factor is selected as the rollover judged index which uses the threedegrees of freedom vehicle model as a prediction model. In order to make the warningmore accurate, T-S fuzzy neural network is introduced and the TTR is optimized bymulti-state parameters. Also, some numerical simulations are given in typical cases.The simulations results show that, the algorithm has higher accuracy and timeliness, itcan effectively increase the precision of TTR for school bus.Finally, the active anti-rollover control model is presented on basis of warningalgorithm. In this paper, the integrated control strategy which uses fuzzy self-adjustingPID and front wheel braking is adopted. The rollover stability factor is selected as thefeedback control targets and the optimized TTR as the trigger condition. The roll statecould be controlled by the anti-rollover moment applied to front wheel which isexported from the simulation model of EMB braking. Finally, the active anti-rollovercontrol model is validated in closed loop using Matlab/Simulink. At the same time, thecontrol effect is analyzed. The simulation results show that the control algorithm has good robustness, effectively improve the poor driving characteristics and lateralstability of school bus to prevent the rollover accident.